Alarm signaling system



kc. F. FFoLLloTT 2,122,460

ALARM SIGNALING SYSTEM Filed Dec. 4, 1956 July,5, 1938.

3 Sheets-Sheet 1 maar 'gli

INVENTOR. CHARLES F.' FFOLL/UTT ATTORNEY.

July 5, 1938. c. F. FFoLLloTT ALARM SIGNALING SYSTEM Filed Dec. 4, 19363 Sheets-Sheet 2 N .mi

July 5, 1938. j c. F. FFoLLloTT ALARM SIGNALING SYSTEM Filed Dec. 4,1936 3 Sheets-Sheet' 3 INVENTOR CHARLES E Frou/07T ZM ATTORNEY.

Patented July 5, 1938 UNITED STATES PATENT OFFlCE ALARM SIGNALING SYSTEMApplication December 4, 1936, Serial No. 114,145

11 Claims.

This invention is concerned with alarm signaling systems and moreespecially an alarm system in which a plurality of alarm stations areprovided and arranged for signaling alarm headquarters, and the generalobject of the invention is to provide new and improved circuitarrangements for systems of the foregoing character.

A further object of the invention is to provide an alarm system overwhich may be transmitted two classes of alarms, and in which telephonecommunication may also be established between an alarm station and alarmheadquarters.

An additional object of the invention is to provide new and improvedarrangements for supervising the alarm circuits against troubleconditions thereon.

These and other objects and features, not speciiicially pointed out,will be apparent by referring to the accompanying drawings whichtogether with the detailed description constitute the preferredembodiment of the invention.

The invention is illustrated in three sheets of drawings, comprisingFigs. 1, 2, and 3. The drawingswhen laid out with Fig. 2 above Fig. 3,and with Fig. 1 at the left of Fig. 2, illustrate the apparatus andcircuits of the preferred form of the invention.

Fig. 1 shows a single radial alarm box RB-l connected by an individualpair of Wires RC to terminals of the main distributing frame MDF. Thealarm transmitting equipment shown diagrammatically at RB-l ispreferably housed within a box, so arranged that the opening of theassociated door will cause the engagement of door contacts |03 and |06.After opening the door of the box access may be had to a iire alarmlever arranged to actuate contacts M2. The combined loud speakingreceiving and transmitting unit |053 may be a so called sound power unitsuch as is disclosed in the application of Woodruii et al., S. N.738,030, led August 2, 1934. The telephone equipment proper comprisestwo of the so called sound power units, preferably mounted together inthe form of the telephone hand set ||0, such a hand set is disclosed inthe pending application of Sengebush, S. N. 738,186, filed August 3,1934.. One unit of the hand telephone functions as a receiver and theother as a transmitter.

At the bottom of the figure is shown a series alarm circuit SC acrosswhich are bridged a plurality of series alarm boxes, as the box SB-I. Instructure and equipment the series boxes may be identical with theradial box shown at RB-|, the

circuit, however, has been modified as will be more fully pointed outhereinafter.

Fig. 2 shows terminal equipment TE, located at alarm headquarters, uponwhich may be terminated either a radial circuit, as shown at RC of Fig.1, or a series circuit as shown at SC. The terminal equipment, amongother things comprises the line jack LJ and the trouble jack TJ. Thetelephone cord circuit CC may be plugged into a desired line jack, suchas LJ; and the test cord circuit TC may be plugged into a desired testjack, such as TJ.

The terminal equipment individual to each alarm line also includes analarm relay 223, which is responsive only to an alarm of the secondclass, and, for the purpose of description, will be referred to as there alarm relay.

Fig. 3 shows, diagrammatically, alarm retransmitting equipment alsolocated at alarm headquarters, comprising a plurality of finderswitches, one of which may search for and seize an operated iire alarmrelay, such as relay 223 of Fig. 2, thereby associating the same withthe sender switch which next functions to transmit a code, indicative ofthe fire alarm relay in question, over an outgoing alarm circuit. Alarmtransmitting equipment such as above described is disclosed in thepending application of Lomax et al., S. N. 112,190, iiled Nov. 23, 1936,wherein the iinder sequence switch is shown as Fig. 3, the nder switchas Fig. 2, and the sender and the sender sequence switch is shown inFig. 4.

It is believed that a most thorough understanding of the invention canbe obtained by describing the operation resulting first, from thetransmission of a class one alarm; and second from the transmission of aclass two alarm.

Transmission of class one alarm The transmission of class one alarms canbest be explained in connection with a patrol box system, here it isessential that emergency or wagon calls may be initiated by the ocerwith the minimum of exertion. Assuming a case of this kind, it is onlynecessary for the oiilcer to open the door of the alarm box RB-I,whereupon a circuit is established from the positive side of battery B,through relay 200, choke winding 202 of repeating coil R-|, springs 203of test jack TJ, conductor |00, jumper |0|, line l,

conductor |02, door contact |03, choke |04, break contact of telephoneswitch hook |05, door contact |06, line conductor |01, jumper |08,conductor 204, springs 205, of test jack TJ, winding 206 of repeatingcoil R-I, choke 201, through relay 208 to the negative side of batteryB. Relays 200 and 208 will now energize and. close obvious; circuitsthrough both windings of relay 209 to battery. The two windings of relay209 will assist each other and cause the complete operation of the saidrelay, whereupon a circuit is closed from ground at break contact ofamature 2li), armature 2II, break springs 2|2 of line jack through linelamp 2|3 to battery. The lighting of line lamp 2|3 is, in itself,information sufiicient to warrant the dispatching of the patrol wagon tothe physical location of alarm box RB-I associated therewith. Theoperatorin attendance, however, in an attempt to gain additionalinformation will select an idle'cord circuit, such as the cord VcircuitCC, and insert the answering plug P-I into the line jack LJ. After whichthe operator will depress the talking key K-l and challenge. Thischallenge will be made audible at alarm box RB--l by the loud speakingsound powerunit It: The said unit will also act as a microphone to pickup any word-'spoken inthe vicinity-cf alarm box-RB-L In the eventv that`no emergency exists the oiocer, upon openingf-- the box, will` removethe hand set telephone llilfrom the switch-hook, thus bridging the sameacrossthe line in place of the loud speakingsound power unit |09,vthereby insuring bettery transmission than could be ex'- pectedY overthe loud speaking' unit. Upon completion ofgtheconversation` the oiTlcerwill restore the telephone handset to the switch hook andn close thedoor of alarm box HB1-i, therebyV causing the deenegization of relaysZeil and V298.Y Relay 209- will next.- deenergize and closea-disconnectY circuit :from ground at armature 2 i4, sleeve of -jack LJ,sleeve ofplug P-|, through disconnect lamp 2HE to battery. The lightingofthe disconnect lamp-2|5 will indicate that the door ofalarm box RB-Ihas been closed and the-operator-will remove the plug P--l from the.jack LJ; f

vInka system such as we have been discussing itis desirable-thatprovision ber'made'whereby the operator at alarm headquarters may recallorsignal-the various alarmstations.Y In caseY it is-desired to recallalarm box RB-l the operator will;select an'idle cordV circuit, such asthe cord circuit TC, andw-ill insert the calling p .lugP-3 intothetestjack TJ, after which, the ringing keyK-Syfll be-operated to'impressgenerator on line RC. Theringer I atfalarmvbox RE-I willrespondthereto-andsound anaudible signal or code. 1

Transmission of class two alarm n The transmission of class-two alarmscan best be explained lin connection with a fire alarm system. Inyfurtherance of this use the outside of boxRB-l preferably bears-thenotice, To report fire, open'door, pull lever down, and then let go;TheY opening of Ythe door results in the circuit changes previouslydescribed, and the operation ofthefi-re alarm, lever'causes themomentary interruptiony ofi a circuit extending from ground at realarmcontactsll and thence in parallel through condenserslr |13 andfll,windings H5 and lISof repeating coil R-Z, line conductors |02 and Il,jumpers 10| andl, conductors IDilandZlll, springs V2.*il3 and 2115 oftest jack TJ, windings 292 andV 2535 of repeating coil R4L conductorsBil andi 2|8, through normally energized relay 2H);` andthe alternatingcurrent generator A to ground. Relay 2|9 will-"fall away momentarily andolosea circuit from ground at spring 223 of the test jack TJ, armature22|, armature 222 and its make contact through re alarm relay andresistance 225 to battery. Relay 223, upon energizing, will lock itsself up to ground at spring 22@ of test jack TJ by way `of armature 224,and at armature E it will remove direct ground from the circuit of lamp2|3 and substitute therefor groundhthrough interruptor INT.

The iiashing of line lamp 2|3 is, in itself, in-V formation sucient towarrant the dispatching of lire apparatus to the physical location ofalarm box RjlBe--l `associated therewith. TheV operator in attendance,however, in an attempt to gain additional,information, will, as beforeexplained, select an lidle cord circuit and insert the answering plugthereof into the line jack LJ.

A further result of the energization of re alarm relay 2231s theestablishment of circuits by way of armatures 223 and 221, andconductors 396, Bril-z, and-'362. t0 the alarm transmitting :equipmenindicated diagrarrirnatically inig..Y 3, with the result thatanderswitch therein will lsearch for` and nd llire alarm relay223,therebyj associating the same with-the common senderswitch whichnext functions to transmit a code indicative of re alarm v relay i223over an g outgoing alarm-circuit. At-the' end of the'required-number-,ofrounds of the-ccdefthe sender sequence switch ,wi-ll function to shuntout re alarmvrela 223, thereby causing its deenergization. Y

the bottom of Fig. 1 is shown La series alarm circuit SCA-across whichare` bridged a'plurality ofseries alarm ,boxes-which,` in structure andequipment, may be identical jwith the radial box shown at RB| It is tobe noted, however, that only the repeating` coil ofY onebox yhas beenbridged across the line,` andthat the alternating current' circuittherefromY has been seriesed to groundV through the-lire' alarmcontactsof all boz-:es on the line. The series circuit SC mayV bejumpered toV terminal/equipment such as TE of Fig; 2,A andv thefunctioning o f'the series box is identical with that described inconnection with alarm yboxgRlB--vh but it is to be Vunderstood thatthe,lineflampasscciatedwith circuit SC is distinctive of that circuit,and-not ofja particular boxfthereon. f

Supervision of alarm circuits Attention is called to the fact that thealternatingY current circuit through relay 2|9 isV simplexed--tovvground at the mid-point ofV repeating coils R-land R--2, itfollows thenthat relay 2|@Y andthe two repeating coils may be so selected/that,inthe event of-an opencircuitin one line conductor, the inductivereactance of the half coil at each end of the circuit will so reduce thecurrent flow throughrelay. 2|9 as to allow armature 227| to fallaway andcomplete acircuit from ground at spring 2,20 ofv test jack TJ, armature22|, armature 222 and its break contact through line lampY 2|3`tobattery. It isapparent alsoV that relayl Ywill deenergizeV either as aresult oftheloss` of the ground connection at alarm box RB,-.|, or thesimultaneous Vopening of both line conductors.

I t is further to be pointedy out that the Ymidpoint of battery B isconnected to ground and,

lo n

through one winding of relay 209, With the result that the latter relayWill energize only sufliciently to operate armature 2| thereby closing acircuit through line lamp 2|3.

To summarize the foregoing it may be said that the line lamp 2|3 willlight as a result of ground on either line conductor; a simultaneouslyopened circuit in both line conductors; the loss of ground at alarm boxRB-I; an open circuit in one line conductor; the opening of the door atalarm box RB-I or the short circuiting of line conductors |02 and |01.As before explained, the operator, in response to the lighting of linelamp 2|3, will insert answering plug P-l into line jack LJ' andchallenge. If no reply is received to the challenge the operator willwithdraw plug P--| from jack LJ and insert plug P-3 of test cord circuitTC into the test jack TJ associated with alarm circuit RC. By furtheroperation of keys thereon the usual routine line tests may be made as,for instance, the foreign potential test established by key Kf-S.

Attention may also be directed to the fact that the transmission of afire alarm code over the alarm circuit may be initiated either before orafter the operator inserts an answering plug into the line jack. Andfurther, that a false fire alarm can occur only in the event of twosimultaneous line faults, i. e., a short circuit on the line at the sametime that the line is open beyond the short circuit.

While the invention has been shown as used in a combined police and firealarm system, it will be understood that it could be utilized equally asWell in connection with any other signaling system such as Watchmansservice or supervisory signaling.

'I'he invention having been described, that Which is believed to be newand for which the protection of Letters Patent is desired will bepointed out in the appended claims.

What is claimed is:

1. In an alarm system, an alarm station, an alarm headquarters, a linecircuit connecting said alarm station with said alarm headquarters, anormal flow of alternating current over said line circuit, a source ofdirect current potential normally applied to said line circuit, an alarmsignal at said alarm headquarters, means at said alarm station forinterrupting said normal flow of alternating current when an emergencyalarm is transmitted,l means at said alarm headquarters responsive tosaid interruption of said normal ow of alternating current forinterruptedly operating said alarm signal, means at said alarm stationfor permitting a flow of direct current from said source of directcurrent potential when an ordinary alarm is transmitted, and means atsaid alarm headquarters responsive to said direct current flow forsteadily operating said alarm signal.

2. In an alarm system, an alarm station, an alarm headquarters, a linecircuit connecting said alarm station with said alarm headquarters, a

normal flow of alternating current over said line circuit, a source ofdirect current potential normally applied to said line circuit,telephone facilities at said alarm station, telephone facilities at saidalarm headquarters, an alarm signal at said alarm headquarters, means atsaid alarm station for interrupting said normal flow of alternatingcurrent When an emergency alarm is transmitted, means at alarmheadquarters responsive to said interruption of said normal flow ofalternating current for interruptedly operating said alarm signal, meansat said alarm station for permitting a flow of direct current from saidsource of direct current potential when an ordinary alarm istransmitted, means at said alarm headquarters responsive to said directcurrent floW for steadily operating said alarm signal, and means at saidalarm headquarters for establishing telephone communication With saidalarm station over said line circuit.

3. In an alarm system, an alarm station, an alarm headquarters, a linecircuit extending from said alarm station to said alarm headquarters,means for normally feeding alternating current to said line,l meanscontrolled by said alternating current for supervising said line againstopen circuit faults, and means responsive to the turning in of an alarmat said station for feeding direct current over said line circuit tobring in an alarm at said headquarters.

ll. In an alarm system, an alarm station, an alarm headquarters, a linecircuit extending from said alarm station to said alarm headquarters,means normally feeding alternating current to said circuit forsupervising said line against open circuit faults, a battery bridgedacross said line having its mid-point connected to ground, meansresponsive to current fioW from either half of said battery forsupervising said line against ground faults, and means responsive to theturning in of an alarm at said station for feeding direct current oversaid line circuit to bring in an alarm at said headquarters.

5. In an alarm system, a station, a central oilice, a line extendingfrom said station to said oiiice, a simplex circuit including said line,a source of alternating current at said oflice normally connected tosaid circuit, an alarm signal at said office, means at said station forinterrupting the iioW of alternating current in said simplex circuit,and means at said office operated responsive to said interruptions incurrent flow for operating said signal.

6. In an alarm system, an alarm station, an alarm headquarters, atwo-conductor line connecting said station and said headquarters, asimplex circuit including said line conductors, a source of alternatingcurrent at said headquarters, an alarm signal at said headquarters, analarm signal relay at said headquarters connected in series With saidsource of current and said simplex circuit, said relay normallyenergized by current flow from said source to prevent the operation ofsaid alarml signal, means at said station connected in series With saidsimplex circuit for interrupting the 110W of alternating current oversaid circuit, said alarm signal relay deenergized responsive to theinterruption of said current flow to permit said alarm signal tooperate.

7. In an alarm system, a central office, an alarm station, a lineconnecting said station and said office, normally deenergized alarmsignal initiating relays at said oiiice, one of said relays conn-ectedin a circuit feeding direct current to one conductor of said line, theother one of said relays connected in a circuit feeding direct currentto the other conductor of said line, an alarm signal at said ofce,ordinary alarm transmitting means at said station for completing anenergizing circuit for said relays in series, means controlledresponsive to the energization of said relays for operating said alarmsignal steadily to indicate an ordinary alarm, a simplex circuitincluding said line conductors `extending from said office to saidstation, a normal flow of alternating current ,in said simplex circuit,emergency alarm transmitting means at said station for interrupting theflow of alternating current in said simplex circuit when an emergencyalarm is transmitted, emergency alarm signal initiating means at saidoce operated responsive to the interrupting of the alternating currentin said simplex circuit for indicating an emergency alarm.

8. In an alarm system as claimed in claim 7, in which the ordinary andemergency alarm transmitting means at said station is so arranged thatthe ordinary alarm transmitting means is automatically operated prior tooperation of the emergency alarm transmitting means.

9. In an alarm system as Aclaimed in claim '7, in which the meansoperated' responsive to the interrupting of the alternating current insaid simplex circuit is a relay that connects an interrupter to saidalarm signal.

l0. In an alarm system, a station, a central oice, a line extending fromsaid station to said gized.

oiice, #a simplex circuitV lincluding said line, a sourcezof alternatingcurrentrnormally connected to said circuit, an alarm `signal at saidolice, a relay at said oflice included in said circuit normallymaintained energized `loy the flow of alternatingcurrent therein', meansat said station for interrupting the oW of alternating current in saidcircuit, said relay deenergizing responsive to said interruptions incurrent flow, means controlled vley the deenergization of said relayVfor operating said signal, said relay also deenergizing responsive tothe accidental opening of one of the line conductors of said simplexcircuit.

ll. In. an alarm system as claimed in claim 10, in which the accidentalopening of one of the line conductors in `said simplex circuitunbalances theV circuit and thereby -increases the impedance thereofsuciently to prevent sufficient 110WV of alternating current to maintainsaid relay ener- Y CHARLEs r'.Y FFOLLIOTT.

